Jersey Shore' ends its run

“Train wreck.”That’s what I hear, again and again, when I ask people why they watch “Jersey Shore.”

“It’s such a train wreck!” they chortle.

I nod blankly and change the subject.

Am I missing the essential train-wreckiness that has made “Jersey Shore” such an audience-pleasing, buzz-generating hit? Or is my immunity to its charms explained simply by the fact that if I wanted to watch a train wreck, I’d choose a swifter railroad?

But this will all be moot soon. After three years and six seasons of boozy, rowdy wrecktitude, “Jersey Shore” concludes its MTV run at 10 p.m. Dec. 20.

Can it really be just three years since Snooki and memes like “smoosh” and “G.T.L.” drilled their way into our consciousness? Since a group of millenial party animals challenged Speaker of the House John Boehner as the nation’s reigning orange public figure?

Did Barbara Walters really include the “Jersey Shore” gang among her “10 Most Fascinating People” list in 2010? (Did she figure that the full cast of eight might add up to a single fascinating person?)

These, and so many other questions, will be deferred for anyone who might be mulling them, after Thursday.

For the moment, it suffices to just marvel at this phenomenon, which convened these housemates — four brawny dudes, four bosomy gals — at the Jersey Shore (and elsewhere as the series wore on), then, with cameras rolling, turned them loose to be themselves and get their dumb on.

There’s been plenty of G.T.L. (gym, tanning, laundry) during the show’s run. Plus drinking and messing around, of course, and random stabs at verbal self-expression. (Mike “The Situation” Sorrentino: “I got the shirt, but I ain’t wearing the shirt when I go out. This is the shirt before the shirt.”)

I can guess why anthropologically inclined viewers might have taken to “Jersey Shore.” Here is an opportunity to study a primitive life form as it feeds, mates and struggles to communicate. (Ronnie Ortiz-Magro: “Why do you even bother? You’re only gonna get it six times as worse!”)

Viewers must have found something infectious about the hiccupy shooting style, and the background music that telegraphs (if by “telegraph” you mean “whacked in the head by a 2-by-4”) the tone of each scene — comic, emotional, outrageous, dramatic — so viewers never have to give the show more than a fraction of their attention.

At the same time, it undid decades of headway by Bruce Springsteen in ennobling his native state, forever cementing its status as a punch line. (Filming of the series wrapped before Hurricane Sandy, with its many victims and heroes, reminded everyone that New Jersey isn’t defined by a handful of camera-crazy beachside interlopers.)

The show didn’t do a lot to burnish the image of Italian-Americans, either, as the cast let it all hang out with time-worn stereotypes. (Deena Nicole Cortese: “It’s like fingerprints: How are you going to tell a guidette apart without her extensions?”)

And it made the cast members — with skills barely advanced beyond strutting, scrapping, carousing and mangling the King’s English — into stars. Thus were these high-wattage dim bulbs instantly deprived of their last shreds of authenticity as nobodies with nothing to lose, their status at the outset of the series.

Now the housemates of “Jersey Shore” can look back proudly at their accomplishments. They have all done their part to lower the bar, even as they stumbled over it.

And they have enjoyed a dream job. They got paid to party. And the bigger the spectacle they made of themselves, the greater their appeal and, presumably, the fatter their paychecks. (Paul “DJ Pauly D” DelVecchio: “One minute you got three girls in the Jacuzzi, the next minute somebody’s in jail.”)

But the time has come to say goodbye. Or not.

The Season Two premiere of “Snooki & JWoww” (starring “Jersey Shore” alumnae Nicole Elizabeth “Snooki” Polizzi and Jenni “JWoww” Farley) is just around the corner. From the press release: “Fans will see Nicole prepare to become a first-time mom, from nesting to going into labor and ultimately, get to see the first footage of her new son, Lorenzo.” That’s Jan. 8. Mark your calendar.

And in the indeterminate future, MTV plans to launch “The Show with Vinny,” which MTV calls a hybrid talk/reality show that “will shatter the typical talk-show format by taking the biggest celebrities out of the studio and into Vinny Guadagnino’s family home in Staten Island, N.Y.” Alas, certain members of this cast could have the half-life of plutonium.

Meanwhile, MTV is moving ahead with a new gang of wild-and-crazy kids. “Buckwild” premieres Jan. 3 with a group of nine rebellious twentysomethings living in West Virginia.

That’s all ahead. But looking back as “Jersey Shore” exits, the question persists: Why?

Maybe people watched “Jersey Shore” because it was a welcome, wacky liberation. A break from the confines of parents, kids, partner, boss. Within their world, the “Jersey Shore” housemates have been privileged to serve as your surrogate id, treating you to visions of irresponsibility while sparing you from its costs — whether embarrassment, a hangover or an STD.

Call “Jersey Shore” a train wreck, then, albeit with no casualties. But does that beat a show that really takes you somewhere?